Creatinine With eGFR

Casandra

Casandra Test Code AR23262Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 3005478CPT Code 82565

Also known as: GFR EST

Clinical Use

Order Test

Use

This test is used to evaluate kidney function by measuring the level of creatinine in serum or plasma and estimating the glomerular filtration rate (eGFR) using the CKD-EPI equation. The eGFR is adjusted for a body surface area of 1.73 square meters and provides an assessment of kidney filtration function. This is useful in diagnosing and monitoring acute kidney injury, chronic kidney disease, and acute glomerular damage. It is most accurate in individuals 18 years and older and less reliable in patients with unusual muscle mass or those on specific medications affecting creatinine metabolism.

Special Instructions

Patient age and sex are required for accurate eGFR calculation using the CKD-EPI formula. Specimens must be separated from cells immediately or within two hours of collection to ensure reliability.

Limitations

The creatinine-based eGFR is less accurate in individuals at extremes of muscle mass or those who have restricted protein intake, consume creatine supplements, undergo extra-renal metabolism of creatinine, or take medications affecting renal tubular secretion of creatinine. Accurate GFR estimation requires consistent day-to-day creatinine levels.

Test Details

New York Approved

Methodology

Automated Analyzer (Clinical Chemistry)

Biomarkers

2 components

Creatinine, Serum or Plasma • Clinical ChemistryeGFR by CKD-EPI Creatinine 2021 • Clinical Chemistry

LOINC Codes

Order Codes

2160-0
98979-8

Result Turnaround Time

1 day

Specimen

Serum

Volume

1 mL

Minimum Volume

0.2 mL

Container

ARUP standard transport tube

Collection Instructions

Collect in plasma separator tube or serum separator tube and allow to clot completely at room temperature. Separate serum or plasma from cells ASAP or within 2 hours of collection.